Phytase Cuts Phosphorus To Better Manage Manure

Phytase is an enzyme which helps hogs use phytate phosphorus present in feed, thus allowing nutritionists to lower the phosphorus levels in diets. The result is a possible phosphorus reduction in hog manure, up to 30%, according to Mike Brumm, Extension swine specialist at the University of Nebraska. Phytase helps the hogs break down and use more phosphorus, so there's less of it left in the manure,

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Phytase is an enzyme which helps hogs use phytate phosphorus present in feed, thus allowing nutritionists to lower the phosphorus levels in diets. The result is a possible phosphorus reduction in hog manure, up to 30%, according to Mike Brumm, Extension swine specialist at the University of Nebraska.

“Phytase helps the hogs break down and use more phosphorus, so there's less of it left in the manure,” says Keith Zylstra of Sibley, IA, who has two 3,300-head contract finishing sites with Prestage-Stoecker. Reducing phosphorus levels is important to Zylstra, who also feeds about 1,500 head of cattle. “Phosphorus is one of our biggest management concerns,” he says. “I'm confident this move by Prestage-Stoecker will help us out.”

To help growers manage phosphorus levels, Prestage-Stoecker Farms spent about $105,000 to equip their Algona, IA feedmill to add phytase to the finishing feed.

“We've been using it (phytase) for about a year and a half,” says Conley Nelson, director of Iowa operations for Prestage-Stoecker. “It's definitely going to reduce phosphorus levels (in manure). It will allow for a more balanced application rate and allow growers to use nutrients more efficiently.”

Steve Borhave of Ashton, IA, another Prestage-Stoecker contract grower, says a 30% phosphorus reduction will give him more flexibility in applying the manure from his 3,300-head finishing unit. Currently, Borhave uses no commercial fertilizer, but hopes the lower phosphorus levels will allow him to put more manure on corn ground and allow him to fertilize the crop with additional nitrogen.

Environmental Guidance

Zylstra says his nutrient management practices have improved. “We have always been livestock people and appreciated the value of manure, but we've become much more aware. We handle all of our manure better,” he says. “It's taught me to employ better recordkeeping throughout the whole farming operation.”

Zylstra says the organic matter content of his soil is much higher since he started using hog manure as fertilizer for his corn ground in 1996. He applies 5,000 gal./acre of hog manure using phosphorus as the limiting nutrient and top-dresses 50 units/acre of nitrogen. In the past five years, phosphorus values have ranged from 50-90 units/1,000 gal. of manure.

Using hog manure over commercial fertilizer costing $55/acre, Zylstra realized about a $15/acre savings after paying the $40/acre application cost.

Zylstra also rents some land about 12 miles from his hog operations. “We have always struggled to get it through a dry August,” he explains. “It's light ground and the organic matter was always low.” After rotating corn and soybeans and applying 5,000 gal./hog manure/acre, he's increased corn yields by 35 bu./acre. The only added commercial fertilizer is nitrogen in timed applications.

“Last year it was one of our best-yielding pieces of ground. The corn was 165 bushels (per acre) when most around here was 130 bushels,” Zylstra notes. “It's been eye-opening for local farmers to see how well our crops are doing and find out how little commercial fertilizer we buy. We are making our land better. I wish we could help more people understand that by monitoring, we are building up the value of the land.”

Environmental Expertise

The company has seven members on the environmental staff, four of whom are certified crop advisors (CCAs). “They understand the laws,” Nelson explains. “They meet with neighbors if there's an issue. They do a lot of education. They work directly with the Iowa DNR field offices and with the county NRCS personnel.”

When the environmental staff members visit contract operations, growers appreciate their “third-party” perspective. “We try to be another set of eyes,” Nelson says.

“They (the company environmental staff) take us through every step of developing a manure management plan,” Zylstra says. Plans are kept in a three-ring binder at each site. A company representative comes to Zylstra's home each fall to ensure plans are kept current. “They take the time to train us and help us manage the program,” he adds.

The environmental program was one of the main reasons Borhave chose to contract with Prestage-Stoecker. In addition to his finishing site, he custom-feeds Holstein steers for a local feed company. “I am so much better on the environment than I was five years ago,” he says of the management of his 550 acres of row crops. Water from a 50-ft.-deep well, providing water for the hog operation, is tested annually for nitrates and bacteria levels. The test has come back clean every year.

Since Borhave started contract hog production in 1998 and began using manure on his crops, “my farming returns have increased by 20%,” he says. “We've seen a five bushel-per-acre yield increase in the soybeans since we started using hog manure for fertilizer. The organic matter has really improved. The quality of the land is better and the soil holds more moisture.”

Hog manure from Borhave's site runs about 40 lb. of nitrogen, 16 lb. of phosphorus and 34 lb. of potassium per 1,000/gal. of manure. He says his soil phosphorus levels are consistently in the medium range. Organic matter on most of the farm is nearly 4.3%.

Prestage-Stoecker submits a copy of Borhave's updated environmental plan on his behalf every year. The Iowa DNR has never visited his operations, “but I'm prepared,” he says. “I've had neighbor farmers come and look at my (manure management) plan. Now that they need to do one, they want to see mine.” He notes the added interest is driven by Iowa law requiring a nutrient management plan.

Posted next to Borhave's manure management plan is an Emergency Action Plan that outlines steps to take in case of a manure spill, for example. The emergency plan includes notifying the local Iowa DNR office, contacting the company environmental resource person and the phone numbers of local excavators and certified manure applicators.

Above-Ground Storage

Prestage-Stoecker uses bio-covers made of chopped straw to reduce odors on manure storage facilities. “We put them on almost two-thirds of the facilities in Iowa,” Nelson says. Preference is given to growers requesting them or in “odor sensitive” areas — where a neighbor might request additional odor reduction methods, he adds.

Zylstra's first finishing site, built in 1996, has an earthen basin. The second site, constructed six months later, was equipped with the Slurrystore. “We were glad the company had the foresight to put the Slurrystore into the program when they did,” he says. A chopped straw bio-cover is used on both manure storage structures.

Borhave's Slurrystore structure holds 1.5 million gal. of manure. “That's a year and a half storage capacity, so I never have to apply in the spring,” he says. “We inject all the hog manure in the fall. Last year I pumped about a million gallons.”

Borhave uses a bio-cover to reduce odor on his site, too. “I must do a decent job of controlling the odor,” he says. “My neighbors built a brand new house about half a mile away.”

Every load of manure is tested at the top one-third, the middle and the bottom one-third. “That information goes into the next year's nutrient management plan,” Nelson says.

“We have a database of all the finishing sites. There's no guessing,” he continues. “If the manure value is low in nutrients, we know there's either been high rainfall levels or a water management problem.” After checking local rainfall totals, the problem is easily tracked and solved.

Borhave, like all Prestage-Stoecker growers, calls in a water usage meter reading to the company's Algona, IA office at least once every turn of a barn. In addition, he checks every nipple waterer in every building before re-stocking. His death loss numbers and freeboard in the Slurrystore are also reported at the end of each month.

Currently, Borhave's pigs use about 1.5 gal./head/day, including water used in the summer misting system. When the current group came in at about 50 lb., they used about 0.8 gal./head/day, he says.